This year's Paris-Roubaix saw little more than a few spritzes of rain on the course and yet at least two of the top-ten ran full-on 'cross frames instead of road bikes: second-place finisher Sebastien Turgot (Europcar) and Rabobank rider Lars Boom in sixth.

Boom has won cyclo-cross world championships in the Junior, U23 and Elite ranks and is obviously well-accustomed to riding such a beast. Mud wasn't an issue for this year's running but even so, Boom says he preferred the handling and feel of his Giant TCX Advanced SL on the cobbles over the Defy Advanced SL the rest of the team was riding – the same bike he rode at last year's Paris-Roubaix.

"It feels good so why should I change it?" he told Cyclingnews at the team hotel in Compiègne the day before the start.

Overall, the geometry of the two bikes is similar with identical head and seat tube angles and the same top tube lengths. The TCX chain stays are one centimeter longer, though, and the wheelbase is a substantial 3.5cm longer for extra stability. Giant doesn't publish bottom bracket drops on its web site but we know the TCX measures an unusually tall 55mm – the Defy is almost certainly significantly lower.

Boom says the other major factor in his decision was tire size. While the rest of the team was using 27mm-wide tubulars over the cobbles, Boom was running even bigger 30mm casings with tons of room to spare on account of the more generous frame and fork spacing and Giant's own team-only machined aluminum cantilever brakes.

Boom wouldn't disclose what air pressure he was running – "I'm not going to say!" he told Cyclingnews – but it was especially low even as compared to other bikes at Paris-Roubaix. We estimated approximately 4 bar (60psi) front and rear.

Boom did, however, start on his Defy Advanced SL in Compiègne "to save some energy." Boom says he and the team chose a good location about 80km into the race to make the swap and he rode the TCX into the velodrome later in the day.

Build kit on both bikes was similar aside from the tires and brakes. As did nearly all of the Rabobank team, Boom switched to a mechanical Dura-Ace drivetrain instead of his usual electronic group and 35mm-deep Dura-Ace carbon wheels were the norm. Boom opted for an all-aluminum cockpit from team sponsor PRO and his saddle of choice was fi'zi:k's Antares k:ium.

Total weight for Boom's TCX Advanced SL was an impressive 7.49kg (16.51lb) without bottles.